Hydroxynorcamphanecarboxylic acids and esters, and polyesters thereof



- 7 3,600,864 I 4 HYDROXYNORCAMPHANECARBOXYIJCAKIDS AND ESTERS, AND PGLYES'I'ERS THEREOF John R. Caldwell and Winston J. Jackson,'Jr., Kingsport, Tenn, assignors to Eastman Kodak Company, Rochester, N.Y.,' a corporation of-New Jersey N Drawing. Filed Apr. 4, 1958, Ser. No. 726,340 5 .4 Claims. ((31. 260 -=-76) This invention relates to hydroxynorcamphanecarboxylic acids and esters, to resinous polyesters thereof, and-to the preparation of these materials.

The new class of monomeric compounds of the invention are represented by the following general formula:

wherein n represents a positive whole number signifying that the unit repeats itself to form a linear chain polymer. The above defined monomeric compounds also cocondense with each other in any proportions. :They also readily co-condense with other materials capable of form.

ing polyesters e.g. with mixtures of various dialkyl esters of dibasic acids and glycols, e.g. with alkyl esters of terephthalic acid and 1,4-cyclohexanedimethanol, the

glycol being present in molecular amount slightly greater than the combined molecular amounts of the 5- (or 6)- hydroxynorcamphane-Z-carboxylic acid ester and the dialkyl ester of the dibasic acid. Although any proportions of the above defined structural unitmay be present in such copolyesters, advantageously there is present 5-45 mole percent of these units, the remainder of the polymer molecule being units formed with the other co-condensed materials. The polyesters and copolyesters of the invention are thermoplastic with melting points of 230-272 C., or even higher, forming clear viscous readily extrudable melts, and are particularly valuable for preparing fibers and films that are 'characterizedby good elasticity, toughness, excellent tensile-strength, good atlinity for commercially available dyes, and excellent dielectric properties. W

It is, accordingly, an object of the invention to provide novel. monomeric S-(or 6)-hydroxynorcamphane-2-carboxylic acid esters. Another object is to provide resinous polyesters and copolyesters that are readily dyeable and highly suitable for preparing fibers, sheets and molding compositions that are characterized by good strength and elasticity and excellent dielectric properties and having relatively high softening temperatures. Another object is to provide a process for preparing the new compounds. Other objects will become apparent hereinafter.

was is? 3,@0,864 P'aiented Sept. 19, 19611 monomeric S-(or 6)-hydroxynorcamphane-2-carboxylic acid'esters by heating bicyclo [2,2,1] hept-S'ene-Z-carboxylic acid in acetic acid containing a small amount of water and sulfuric acid, extracting the reaction mixture: with a dialkyl ether, for example, isopropyl ether, removing the solvent under reduced pressure to give the crude re ture, in the presence of an esterification catalyst such as hydrochloric acid, sulfuric acid, p-toluenesulfom'c acid, etc. Advantageously, the esterification is carried out in an inertsolv'ent medium such as toluene, xylene, etc., thewater formed in the reaction being collected and slim-' inated in a Dean-Stark type of trap. The reaction mixture was then fractionally distilled to separate the solvent and products. In the above reactions, the acetic acid is employed in considerable excess i.e. about 4-10 molecular equivalents of the acid to each mole of the bicycltr [2,2,1] hept-5-ene-2-carboxylic acid. The alkanol employed for the esterification step is advantageously also used in excess i.e. about 3-10 molecular equivalents of. the-alcohol to each mole of the crude acetoxynorcatmi phane-Z-carboxylic acid. The butyl ester prepared with;

=11, n+butanol'is preferred. The higher esters containing from terials.

i In accordance with the invention, we prepare the new 10-12 carbon atoms are valuable plasticizers for cellulose; esters,.and various vinyl polymers. For preparing the homopolyesters and the copolyesters of the invention, we heat the hydroxynorcamphane-Z- one or more of-the other dibasic acid esters e.g. alkyl esters of succinic, adipic, sebacic, terphthalic acids, etc.,. for example, terephthalates represented by the generalformula: r

R10 o 00c 00 R1 wherein each R represents an alkyl group of 1 to 4 car- I bon atoms, such as-the dimethyl, diethyl, dipropylpdis butyl, etc., esters of terephthalic acid, and one or more. glycols-;e.g; e thylene glycol, trimethylene glycol, hexa-' methylene glycol, 1,4-cyclohexanedimethanol, etc., in the presence of catalyst 'such as zinc chloride and titanium.

tetrabutoxide, at temperatures of ZOO-300 C., but preferably 220-290 C., in an inert atmosphere such as nif trogen, fora period of time sufficient to produce a high,

viscosity polyester (at least 0.40 intrinsic viscosity),

ordinarily from 1-5 hours of heating. Advantageously, the heating is carried out in the final stage under vacuum The melts can be extruded to shaped articles directly, as obtained or they can be allowed to solidify by cooling, followed by grinding to a fine powder and then heating' further at temperatures insufficient to melt the powder, under vacuum, to remove the last traces of volatilerna- Thepowder may be stored and remelted as desired. v The following examples'will serve to illustrate furtherour new compounds and the manner of preparing the same. I

Example 1 vAsolution containing 158 g. (1.1 moles) of bicyclo [2,2,1] hept-S-ene-Z-carboxylic acid, 360 cc. of acetic acid, 9 cc. of water and 3 cc. of of sulfuric acidwas heated on a steam bath for 17 hours. About one-half of theacetic acid was distilled off under reduced pressure (base heater at 50 C.). The residue was taken up in isopropyl ether, washed with water four times, and dried with anhydrous sodium sulfate. The solvent was then removed under reduced pressure to give a crude product which was essentially 5-acetoxynorcamphane-Z-carb'oxylic T 3 containing some of phauelmarboxylic acid.

The above prepared crude product was dissolved in a mixture of 360 cc. of n-butanol, 150 cc. of toluene and 41 g. of p-toluenes-ulfonic acid, and refluxed. Water which formed. was. collected in a Dean-Stark trap filled with. toluene. The total reaction time was 6 hours; The solution was cooled, washed with aqueous sodium biCBI- 'bonate. solution, and dried with anhydrous sodium sul fate. After removal of the toluene and excessbutanol by: distillation, the residual liquid was fractionally distilled. The torerun; contained an unidentified material which partially crystallized. to a low-melting solid. The

the isomeric -acetoxynoreammain. fraction of 93 g. (40% yield) oi a colorless liquid,

B..P. 139 C./3 mm., n 1.4766, was S-hydroxynnrcamphane-Z-carboxylic acid butyl ester. Analysis of'this product showed that it contained by weight; 67.7% of carbon and 9.4% ot-hydrogen compared with. calculated for cmn o, of 68.0 and 9.4, respectively.

Example 2 A mixture containing: 1.0. g. of; the. 5.-hydr oxynorcamphauee2-carboxylic acid, butyl ester; prepared. by the.

process: of Example. 1, 0.005 g. ofi zinc acetate and.0..0.0.28,

g. of titanium tetrabutoxide was: stirred. at 220-230 C. in an atmosphere of nitrogen. for: onezhour. A. vacuum. of 0.1 mm. was applied and stirring at 2.40 C. continued. for- 3 hours. The product had ahigh; meleviscosity. anda meltingpoint of 230-240. C.

Fibers of this product were prepared by the melts spinning process. They had a tensile strength 0134.7 g, per denier, an elongation of. 2 1%., and dyed well. with. cellulose acetate dyes.

Films of this: product were prepared, by' an: extrusion: process ofthe melt. They-had excellent dielectric pro:- perties and were valuable as protective coatings under: conditions of high humidity. For example, a filmv of the product with an inherent viscosity oat-0.65 had-,. after: exposure for 8 days at 110 C. and a relative humidity of. 100%, an inherent viscosity of 0.60. Under the same testing conditions, the inherent viscosity inf-commercial polyethylene terephthalate film changed from 0.53 to 0.19.

In place of the said butyl ester; theremay besubstituted' in-the above example alike amount of the-isomericcom pound; 6-hydroxynorcamphane-Z-carboxylic acidbutyl ester to give a similar polyester with generally similar: properties. Also, there may be substituted in theex ample an. equivalent amountof any other of the mentioned methyl, ethyl, propyl, butyl, etc. esters; for-ex ample, S-hydroxynorcamphane-Z-carboxylic' acid methyl" ester to give the corresponding polyester, or S-hydroxye riorcamphane-Z-carboxylic acid hexyl ester to give the corresponding polyester,- etc. All of thcsepolyesters arecharacterizedby being melt-spinnable to, fibers and cap-- able. of being extruded to films that have generally similar properties-as the polyester of the above example.

Example 3 fCJI.., .,,hour,s,. The resulting powdered copolyester melted.

al.:26.0.-272? C. andhad anintrinsicviscosity of 0.72. Strongelastic fibers could be. pulled from the melt.

- The proportions of'components in the above example. canbevariedovera wide. range, for example, excellent Oopplyesterss are. obtained with. starting; components. in.

4 the molar ratios of from 1:9:10 to 9:1:2 of the hydroxynorcamphane-Zwarboxylic acid butyl ester, dimethyl terephthalate and 1,4cyclohexanedimethanol in that order. Thus, the butyl ester component may be present in the polymer molecule in as little as 5 mole percent and as much as 82 mole percent. Also, in place of the said butyl. ester; there can be employed any otherof the mentioned hydroxyn'orcamphane-z-carboxylic acid. allcyl esters- By following the-procedures ofthe above examples for the preparation of. the? homopolyesters and. thecopolyesters, other resinous polyesters having generally similar properties making them especially useful for fibers and films: can be prepared with any of the mentioned suitable connionen'ts. Ifd'esircd, modifying materialssuch as fillers, dyes, lubricants, plasticizers, and the like, may be incorporated into the polyester powders and melts of the invention- Also,- the polyesters of the invention can be molded into stable, shaped articles by conventional molding methods. The film or sheet materials are useful also as' photographic film supports.

What We claim is: 3

1. A linear fiber-forming polyester selected from the group consisting of (1) a homopolyester of a hydroxycamphanecarboxylic acid represented by the following generalformul'at' pnncntss Whereimthe sum; of said" components: (aj'g.

(b?) andicjleqnals .100.- molepercent:

2. A linear:fiberrforming:homopolyester of a norcam-:

phanecarboxylic: acid. represented. by the'following geneeraliformula:

3'. Aprocessifonpreparinga linear.fiber-formingpolyesterwhichcomprisesheating, at. 200-300. C- and inthe:

presence oftitaniumv tetrabutoxide as a catalyst, a men;

omeric. material selected from. the: group consisting 1: of. (11)., a. hydroxycamphanecarboxylic acid ester represented by the. following. general .formula:

whereinr represents: an alkyl. group" containing" from. 1 -12; carbon atoms: and 2) a. mixture of." (it) saidhyl droxynorcamphanecarboxylicr acid" ester, (12) a dic'ai'r boxy-lie. acidls'e'lected'frorn the: group consisting. of anaalkanedicarboxylic acid. containing from 441- carbon atoms. and'terephthalic acid and (c) a glycol selectedfrom the groupcon'sisting. of an alkane glycol containing.

from. 2 .-6 carbon atoms and" l,4-cyclohexanedirnethanol;v said m1xture.-.containing.not less than. 5Y-mole percent of eachnof.v saidfii); (6.) and..'('c) components .andwherein 5 the sum of said components (a), (b) and equals 100 mole percent.

4. A copoiyester of (a) 5-hydroxycamphane-2-carboxylic acid, (b) terephthalic acid and (c) 1,4-cyc1ohexanedirnethanol, in proportions of not less than 5' mole percent of each of said (a), (b) and (0) components and wherein the sum of said components (a), (b) and (c) equals 100 mole percent.

References Cited in the file of this patent UNITED STATES PATENTS 2,180,418 James Nov. 21, 1939 6 McClellan Mar. 23, 1943 Gawey Oct. 24, 1944 Henke Aug. 14, 1945 Sowa May 31, 1949 Salzberg Aug. 14, 1956 Alderson Oct. 29, 1957 Banes July 14, 1959 FOREIGN PATENTS Germany Jan. 24, 1957 Netherlands Sept. 16, 1957 

1. A LINEAR FIBER-FORMING POLYESTER SELECTED FROM THE GROUP CONSISTING OF (1) A HOMOPOLYESTER OF A HYDROXYCAMPHANECARBOXYLIC ACID REPRESENTED BY THE FOLLOWING GENERAL FORMULA: 